mISDN: Cleanup debug messages

This patch make debug printk's KERN_DEBUG and also fix some
codestyle issues.

Signed-off-by: Karsten Keil <keil@b1-systems.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/isdn/mISDN/timerdev.c b/drivers/isdn/mISDN/timerdev.c
index bbd99d3..5b7e9bf 100644
--- a/drivers/isdn/mISDN/timerdev.c
+++ b/drivers/isdn/mISDN/timerdev.c
@@ -259,7 +259,7 @@
 	return ret;
 }
 
-static struct file_operations mISDN_fops = {
+static const struct file_operations mISDN_fops = {
 	.read		= mISDN_read,
 	.poll		= mISDN_poll,
 	.ioctl		= mISDN_ioctl,